<!DOCTYPE html>
<html lang='en'>

<head>
    <meta charset='UTF-8'>
    <meta http-equiv='X-UA-Compatible' content='IE=edge'>
    <meta name='viewport' content='width=device-width, initial-scale=1.0'>
    <title>Document</title>
    <script src='../vue.js'></script>
</head>

<body>
    <div id='app'>
        <input type="text" v-model.number.lazy="score">
        <div>
            <template v-if="score>90">
                <h1>成绩是</h1>
                <p>A</p>
            </template>
    
            <template v-else-if="score>70">
                <h1>成绩是</h1>
                <p>B</p>
            </template>
    
            <template v-else-if="score>50">
                <h1>成绩是</h1>
                <p>C</p>
            </template>
    
            <template v-else>
                <h1>成绩是</h1>
                <p>D</p>
            </template>
        </div>
    </div>
    <script>
        Vue.config.productionTip = false;
        const vm = new Vue({
            el: '#app',
            data() {
                return {
                    score:null
                }
            }
        })
    </script>
</body>

</html>